Introduction to GeoExplorer - DST...
Transcript of Introduction to GeoExplorer - DST...
Introduction to GeoExplorer
Tutorial ID: IGET_WEBGIS_004
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IGET_WEBGIS_004 Introduction to Geoexplorer
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Introduction to GeoExplorer
Objective: This tutorial will introduce you to basic graphic user interface of GeoExplorer and how to add and style
the layers and also introduce editing, querying, printing and publishing maps.
Software: OpenGeo Suite 3.0
Level: Beginner
Time required: 2 hours
Prerequisites and Geospatial Skills
Basic computer skills
Basic Html Knowledge
IGET_WEBGIS_002 and IGET_WEBGIS_003 should be completed
Reading
1. Introduction to the OpenGeo Suite, Chapter 4: GeoExplorer, pp. 79 – 110.
http://presentations.opengeo.org/2012_FOSSGIS/suiteintro.pdf
Tutorial Data: The tutorial data of this exercise may be downloaded from this link:
Link
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Introduction
GeoExplorer is a one of the components of OpenGeo suite, which offers a browser based platform to view, edit,
publish and also to perform simple spatial task on the web GIS data. GeoExplorer can load maps from multiple
sources such as MapQuest layers, Open Street Map, Google, Bing & MapBox layers and local GeoServer layer or any
other GeoServer from remote location.
Geoexplorer GUI
1. Start OpenGeo Suite Dashboard via, Start All Programs OpenGeo Suite 3.0 OpenGeo Suite
Dashboard Click on ‘Start’ button to start the server.
2. Click on the ‘Launch’ button in GeoExplorer.
3. Now ‘GeoExplorer: Welcome’ page will be opened in your default web browser.
4. The GeoExplorer’s Graphic User Interface (GUI) can be divided into the following sections
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4.a
4.b 4.c
4.d
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a. Button Bar is located on the top of webpage. It contains tool from left to right, the first one is
GeoExplorer. It gives basic information about GeoExplorer and the second one is Map, it aims
to publish/export and save your custom maps and the third one Print is used to print the maps.
We can use Identify tool to get information about features and Query can be used to fire simple
queries on the data. Measure tool helps to measure distances and areas and where Edit tool can
be use to edit the active layer.
b. Layer Panel is organized into two sections. The first one Overlays organizes any layer added from
the local GeoServer or any other remote, WMS or WFS server and Base layers include any layer
added from a known tile-map server viz., Google, Bing, Yahoo, MapQuest, or OpenStreet Map.
Add layer can be used to open a list of available layers. Remove layer button removes the
currently selected layer. Layer properties open the layer properties dialog and Edit
Styles opens a GUI based layer style editor which requires login credentials.
c. Map Panel is located right to the Layer Panel here maps added to the GeoExplorer from multiple
sources will be displayed. You can see the scale on the right bottom of the map and on top left
you can see the navigation controls.
Click on up arrow
4.a
4.b
4.c
4.d
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d. Table Panel is shows the attribute data of layer. You have to click on the up arrow to expand
(see) the table panel. It will be empty if no layer is selected.
Adding a Layer
5. To add a layer click on ‘Add Layer’ button in Layer panel
6. Now you will be presented with a list of available layers select ‘Local GeoServer’ from the drop down
menu box select ‘Urban’ layer from BVU_Vector_wp workspace that we created in the last tutorial
IGET_WEGGIS_003: GeoServer. Now click on ‘Add layers’ button located bottom of Layers panel
Click on ‘Done’ to finish
7. Now you can see ‘Urban’ layer listed under ‘Overlays’ and also add to the Map window section
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Styling layers
8. To style the layer you must have the administrator rights. Login to GeoExplorer using the button ‘Login’
located right in the ‘Button Bar’. The default username and password are ‘admin’ and
‘geoserver’ respectively.
9. Now right-click on the ‘Urban’ layer under ‘Overlays’ Click on ‘Edit Styles’.
10. Click on ‘Duplicate’ button under ‘Styles’ section Enter ‘Title’ as ‘Urban_BVU’ and ‘Abstract’ as ‘A
style for Urban layer of BVU toposheet’ as shown below Click on ‘Save’ button on the right bottom
Now you will notice the ‘The new style name ’ added to the dropdown menu.
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11. Now select ‘Polygon’ under ‘Rules’ Click on ‘Edit’ Select ‘Basic’ tab Change the name as
‘Urban’ Click on ‘Color box’ under ‘Fill’ section place cursor pointer on a light red color and click on
left mouse button in the prompt ‘Color Picker window’ Now click on ‘Color box’ under ‘Strokes’ to select
‘dark red color’ from the color piker and keep other options as default Now Click on ‘Save’ and close
the ‘Color Picker’ window to finish.
12. Now you can see the ‘Urban’ layer in newly added style in Map panel as shown below.
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Creating and Editing Data
13. In this section we will learn how to create a feature followed by modifying and deletion in GeoExplorer .
Click on ‘Layer’ button to return to the basic view.
14. Select ‘Urban’ layer under Overlays Click ‘Edit’ in button bar and select ‘Create’ from dropdown
menu.
15. Now zoom to the any part of Pune by using ‘Zoom’ tool Now digitize a polygon of any shape
(Just for demo) use left mouse button to place vertices and double click to finish the digitization Now
you will be presented with a popup window leave it empty Click on ‘Save’ in the popup window. In
this way we can create the features. We can use high resolution published imageries as a base layer for
digitization.
16. If you want to change the shape of the digitized feature click over ‘Edit’ Drag and place the vertices on
right positions (since we don’t have any base image, here make it as approximate square) Click on
‘Save’ in the popup window.
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17. Since this is a random block digitized for demonstration purpose click on ‘Delete’ button to delete it
Click on ‘Yes’ in popup window to confirm deletion.
Query the layer
Finding a particular feature can be difficult especially when you don’t know where it is located. In such cases we
can use ‘Query’ tool. In the section we will learn a simple query to locate the world cities having population 10
millions and above.
18. Add ‘World - Cities’ layer from Local GeoServer to the ‘Overlays’ (Refer Step 5-6).
19. Click on ‘Query’ tool. You can see a Query panel and Table panel will pop up as shown in below image.
20. Select ‘Population’ from the drop down menu and condition as ‘>=’ enter a value ‘10000000’. Now click
on the ‘Query’ button. This query will gives you the cities with population ten million and above in the
current extent of map.
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21. The results will shown in the table
Printing Maps
22. Right click on ‘Urban’ layer under Overlays select ‘Zoom to layer extent’.
23. Now click on ‘Print’ button in button bar In the popup window select the ‘Paper size’ as ‘A4’
and ‘Resolution’ as ‘300 dpi’. 24. Name the Map as ‘IGET GeoExplorer Tutorial’ and write suitable description in the text box located
below to the name and click on ‘Print’ to save the map.
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Publishing Map/ Export Map
Publishing/ Exporting map will generate an interactive web map that can be integrated with other web
application without any hassle.
25. If you are not login to the GeoServer, login as admin before proceeding further. Now Click on ‘Map’
button and click on ‘Export Map’ from the dropdown menu in the button bar.
26. In the ‘Export Map’ popup window ‘check’ the tools you want to include in the map then click on ‘Next’
to preceed further.
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27. Select the desired map size from dropdown list of ‘Map size’ as you select the map size you can see the
corresponding changes in the height and width of the map in the textbox below. Here we will select the
‘Premium’ size. Now copy the code in the text box
28. Open the html file ‘map_publish_bvu’ supplied to you with tutorial data in notepad by right-click on the
map_publish_bvu open with notepad. Now ‘Paste’ the code at the location as shown in image
below
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29. Now ‘Save’ the file and ‘Close’ notepad.
30. Now double click on the ‘map_publish_bvu.html’. It will publish the map in your default web browser.
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